Abstract: A wideband antenna with reduced diameter and volume compared to prior art tennas and having non-critical dimensions resulting in ease of manufacture and tolerance to damage in portable applications and during installation. In one embodiment the antenna is comprised of a vertical element, a number of equally spaced, equal length horizontal elements in the form of a disc and a number of equally spaced, equal length round plane elements in the form of a cone. The vertical and horizontal elements are connected to the inner conductor of a coaxial transmission line and the conical elements are connected to the outer conductor transmission line. In a second embodiment of the present invention, the vertical element is deleted and a parallel inductor is connected between the transmission line outer and inner conductors.

Abstract: A visual display system detects and continuously displays the location of a breach in a protected building or secure area. Each of a plurality of exclusive OR gates is connected to a separate reed-type sensor switch. Each exclusive OR gate output is connected to a flip-flop network, each of which in turn is connected to a light emitting diode. Activation of a sensor switch results in lighting only of the light emitting diode associated with the area breached. A mechanism is also provided for preventing the generation of false alarms by transients or inadvertent momentary opening of any of the sensor switches.

Abstract: A raster generator for producing a raster-type display on a random scan dlay terminal where the raster can be oriented at any selected angle of rotation. The rotating raster generator responds to a digital input signal representing the desired angle of rotation which may represent, for example, the turning or rolling motion of a vehicle. The generator operates digitally to provide an output comprised of two sets of digital signals, each signal set representing an axis rotated in an amount directly related to the value of the input angle. The signals are presented as inputs to the deflection coils of a cathode-ray tube (CRT) or like display.

Abstract: A planar millimeter wave microstrip triplexer for separating three contigs bands of frequencies (lower, middle and upper bands). The middle band is separated by the use of a diplexer comprising two quadrature couplers connected by dual identical planar bandpass filter sections. A second diplexer comprised of two edge-coupled filter sections is connected to the isolated port of the input quadrature coupler of the first diplexer. Signal components contained in the upper and lower frequency bands appear at the respective outputs of the second diplexer.

Abstract: A wideband VHF antenna operable simultaneously on multiple frequencies hag an instantaneous bandwidth greater than one octave and having a total length less than one-quarter wavelength at the lowest operating frequency. A wideband impedance transformer is connected to the antenna total radiating structure at the feed point. The radiating structure comprises a conductor secured to a dielectric whip. The conductor is comprised of two sections of length L1 connected by a short length of electrical connector to form a large loop. The radiating structure further comprises a second electrical conductor of length L2 connected by another short length of electrical connector so as to form a small loop. The length L2 conductor is disposed in the neutral plane between the two conductor sections of length L1.

Abstract: An operator console, a general purpose digital computer and a radio set irface are connected to perform the modulation and demodulation of the differential coherent quadrature phase shift signal used to transmit the digital information over a computer-to-computer radio link. The console is used to initiate communications and to control and monitor link operation. The computer performs all of the signal processing and control functions. The radio set interface performs analogue-to-digital (A/D) and digital-to-analogue (D/A) conversions for the received and transmitted signals, respectively. The programmable data terminal set (PDTS) also controls the data link operation and sequencing and tests its own performance during operation.

Abstract: A noise rejection circuit for a communications receiver in which the input o the receiver is continually sampled by a sweeping heterodyne oscillator to develop a difference frequency noise signal which represents the input noise over a wide frequency band. The receiver input is also processed by a conventional heterodyne oscillator to develop an output at an intermediate frequency that is comprised of the desired signal plus the noise component. Further processing of both the swept heterodyne oscillator and the normal heterodyne oscillator outputs in a differential combiner serves to remove the noise from the desired data signal.

Abstract: A millimeter wave MIC diplexer constructed in either stripline or microstrip comprising two edge coupled bandpass filters separated by specific lengths of transmission lines designed to separate two bands of frequencies. Input signals having frequencies within a first band are passed through one of the bandpass filters while being isolated from the other and input signals having frequencies within a second band are passed through the other bandpass filter while being isolated from the first filter.

Abstract: An antenna array comprising a plurality of antenna elements formed from ml-clad boards and conductive pins. Two metal-clad boards are placed together to form a sandwich, the metal-clad surfaces of the boards forming the top and bottom walls of a waveguide. Pins are placed perpendicular to the clad surfaces to form the sidewalls. The signal is introduced by a coaxial probe in the broad wall of the waveguide in a conventional manner. A row of pins defines the backwall of the waveguide.

Abstract: A video-blanker system for supplying blanking pulses to receivers including a main delay one-shot for responding to a pretrigger pulse and establishing a time delay in response thereto by providing an output pulse of a predetermined width and an auxiliary delay one-shot having its input AND coupled to the pretrigger pulse and to the output of the main delay one-shot for responding to pretrigger pulses occurring during the timing cycle of the main delay one-shot. The outputs of the main and auxiliary delay one-shots are trailing edge discriminated and OR coupled to initiate a pulse width one-shot which supplies the required blanking pulse. The main and auxiliary delay one-shots include means for reducing the recovery times thereof, without affecting the quasistable periods.

Abstract: A battlefield identification friend or foe (BIFF) system comprising a radar nit including a switch for selectively connecting an interrogation encoder to the modulator of a radar unit and a response decoder also located at the radar site. At a remote station is a transponder which includes an interrogation decoder which, when properly interrogated, activates the transponder/transmitter which then transmits a coded response message.

Abstract: An interface for transmitting data in either a clock edge triggered synchous transmission mode or an asynchronous transmission mode. An edge triggered register has its input connected to a source of digital data and its output connected to a two-to-one multiplexer. A bypass path connected between the digital data source and the multiplexer is provided around the edge triggered register. The two-to-one multiplexer is selectively actuable to provide either asynchronous transmission by connecting the bypass path to an output means or to provide synchronous transmission by connecting the output of the edge triggered register to the output means.

Abstract: A broadband high pass microwave filter and method of manufacturing thereof hat maximizes the frequency separation between the desired passband of the filter and spurious passbands. A strip of dielectric material has alternately spaced capacitor plates formed on both sides thereof such that parallel plate capacitors are formed at the overlapping sections of the capacitor plates. The dielectric strip is folded in accordian-like fashion and inductive leads are electrically connected to the capacitor plates at each of the folds. The folded dielectric strip is mounted on an MIC substrate, the end plates of the strip are electrically connected to microstrip conductors on the substrate and the inductive leads are connected to the ground plane of the microstrip substrate to thereby form the high pass microwave filter.

Abstract: A dual mode missile guidance system employing a passive anti-radiation ser for midcourse guidance and an alternate sensor for terminal guidance. A broadband, body mounted conformal antenna comprises the midcourse sensor, and the alternate sensor is mounted on a stabilized platform within the missile radome. Detected video guidance signals from the midcourse sensor are video processed and utilized to adjust the system phase shifters for null tracking as well as for driving the stabilized platform to keep the alternate sensor directed at the target. Upon the occurrence of a predetermined condition, a handover switch connects the detected video guidance signals provided by the alternate guidance sensor processor for video processing and for control of the stabilized platform. Auto pilot signals are derived from the rate gyros mounted on the stabilized platform.

Abstract: A microstrip hybrid ring coupler providing the same function as a convental magic Tee in waveguide or a coaxial rat-race. The ring is comprised of four equal electrical length arcs between the input-output ports. The 180.degree. phase shift is introduced in one of the four ring arcs by a tightly coupled parallel strip conductor which extends towards the interior of the ring and has an electrical length of .lambda./4 where .lambda. is the wavelength at the midband operating frequency of the coupler.

Abstract: Radiant energy sensors situated in first and second orthogonally positioned rrays may be activated by radiant energy projected thereupon by radiant energy sources spatially separated therefrom, each of the sensors providing a first output level when activated and otherwise providing a second level of output. A control element subject to an operator's manipulation is situated between the sensors of both arrays and their respective activating sources, and is disposed to be movable in two spatial dimensions to selectively shadow sensors of both arrays. The combined outputs of the sensors of the first and second array comprise a control signal in digital form, wherein discrete positions of the control element are represented, the digital control signal being coupled through a digital-to-analog converter to generate analog signals determinative of the motion of a light element on the screen of a cathode ray tube (CRT) display device and functionally related to control element position.

Abstract: An impact deflection absorber and stabilizer for providing an interface between two items, surfaces, etc. permitting regulated and controlled travel (energy absorption) along its longitudinal axis and constraining motion in all other directions. An energy absorbing spring is positioned within a housing comprised of two cylindrical mating surfaces forming a friction surface therebetween. A collar clamp joins the two cylinders together and adjustably controls the amount of friction between the two surfaces thereby providing control of the energy absorbing capability of the device. The clamp also has the effect of strengthening the device along non-longitudinal axes, such that all axes have a resonant or fundamental frequency higher than that along the longitudinal or primary axis whereby the device will yield longitudinally regardless of what direction the forces are emanating from.

Abstract: A serial to parallel converter receives a succession of digital bits in serial form comprising discrete data formats and control formats through its input terminal, which is coupled to a data shift register and to a control shift register. When a data format is coupled into the input, a register enable circuit enables the data register to load and convert sets of changeable data bits, comprising part of the data format, to parallel form. When a control format is coupled into the input, the register enable circuit enables the control shift register to convert sets of changeable control bits, comprising part of the control format, to parallel form. One of the changeable bits in every control format immediately followed by a data format comprises an incoming data indicator.

Abstract: A method and apparatus for data compression which utilizes a random walk ough Pascal's triangle which is directed by the incoming random source sequence. The random walk starts at the apex of Pascal's triangle and proceeds downward according to an algorithm until it terminates at a boundary which has been constructed in such a way that the encoding of each source sequence can be accomplished in a fixed number of bits. The fixed-length encoded block consists of a prefix to determine the boundary crossing point in Pascal's triangle and a suffix which represents the encoded form of the input sequence relative to that starting point. Theoretically optimal entropy encoding is achieved by this method.

Abstract: A controller interface for demand assigned multiple access (DAMA) devices is provided. The controller interface includes a plurality of matched pairs of receive/transmit FIFO memory devices. The receive FIFOs, controlled by a clock signal output by the DAMA devices, accept serial format data and output parallel format data onto a first parallel data bus internal to the controller interface. The transmit FIFOs, controlled by an independent clock that generates clock pulses at a rate that is approximately equivalent to that of the clock signal used to control each of the receive FIFOs, accept parallel format data from a second parallel data bus internal to the controller interface and output serial format data for ultimate use by the DAMA devices. A first buffer receives parallel format data on the first internal parallel data bus and outputs same onto a parallel control data bus external to the controller interface.